What is this thing, being an American?

I purchased today, out of a perverse sense of something I'm still not sure what, one of those reproduction tin signs. Many such are of old advertising logos, or folksy slogans. This one was definitely 'retro', in the sense of being of an earlier era, but freshly recreated because of renewed interest in its content.
The sign said, in proud red-white-&-blue lettering, America for Americans.
Now, I didn't buy it from a white-supremacist website, nor a strident activist at some gun show. I bought it, pulled from a pile of otherwise innocent signs, from an upscale 'home supplies' store in a local mall.
Given our old friend Usama bin Laden's recently renewed threats against 'America', and the marchers in Pakistan and elsewhere shouting their support of "Death to America", this is a curious time to be an American.
We all, especially the current administration, fully expected the 1945-era "hurray, the Americans are here!" celebrations we saw in the first few days after we took Baghdad (which we should have done back in the administration of Bush the Elder, when we had everybody already there and, by all reports, Saddam was already packed and at the airport getting out of Dodge). However, what we failed to realize is that those were really Nineteen Forty Four celebrations, by the Kurds and the Shi'ites in the south, just like those we saw in Paris and Amsterdam in that year. What happened in the center section of Iraq, however, is much more like what we fully expected to find in Nineteen Forty Five, when Patton's army went into Germany: sullen, armed 'werewolves' ready to fight to the death to rid their soil of the hated invader.
Thus we should not be surprised when the religion-poisoned multitudes do not much like us being 'over paid, over sexed, and over there', as even our British allies thought in 1945. For those fully expecting to be met in Paradise by seventy-odd virgins, strapping on some explosives and driving into the midst of an armored column on the road to Baghdad Airport will seem like a hell of a good idea.
In the face of that virulent anti-Americanism, defining what being an American is, I believe, is an important task.
More on this as we go along.
In the meantime, remember this: America, and thus being American, is mostly an idea, conjured up by less than a hundred of those Dead White Men we are currently supposed to abjure as politically incorrect. They wrote (mostly, Thomas Jefferson wrote) a few thousand words in a handful of documents which defined the notion of what it meant to be an American. Few Americans these days can quote even a dozen of those words, other than the many politicians and criminals (or am I being redundant?) familiar with every detail of the Fifth Amendment. But it all started with these: We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness.
It doesn't get any clearer than that...